甘薯线虫病，俗称“糠心病”。甘薯苗受害后，出现条状晕斑，斑内显黑色斑纹。薯茎受害后髓部初期白色，后变为黑褐色，干烂。同时近地面部有斑痕，易折断。薯蔓部受害后，表皮龟裂形成不规则状褐色斑点，易折断。薯块受害后，从顶端和揭子部位侵人的，切开可见白粉质病斑... Sweet potato nematode disease, commonly known as “heart disease”. Sweet potato seedlings victims, the emergence of strip-like halo, spotted black markings. After the stems of stalks damaged early white, dark brown, dry rotten. At the same time near the Ministry of the surface of the mark, easy to break. Potato Ministry suffered victims, the formation of irregular cuticle brown spots, easy to break. Potato victims, from the top and the site of invasion of the dissection, cut open the visible white powder disease ...